WASHINGTON (Reuters) - President Barack Obama will meet with the leaders of Honduras, Guatemala and El Salvador next week to discuss cooperation on the influx of child migrants from Central America into the United States, the White House said on Friday.

The meeting comes as the number of unaccompanied minors crossing the border into the Rio Grande Valley in Texas has begun to drop off, senior administration officials said, seeking a victory in a crisis that has consumed significant attention from the White House and the Obama administration in recent weeks.

In June roughly 2,000 children were crossing the border on a weekly basis, one official told reporters on a conference call. By the second week in July those numbers had dropped below 1,000 and were continuing in that direction, he said.

"We think that this is an important trend," the official said.

The officials tied the drop to a number of factors, including U.S. information campaigns about the dangers of the journey for the children and clear policy statements that coming to the United States would not give the migrants a pathway to citizenship.

The officials said weather-related declines were also a factor. Traditionally fewer border crossings occur in the hotter summer months.

Obama has come under fire from Republicans, who say his immigration policies have encouraged the flood of minors to make the journey to the United States.

The president's meeting with Guatemalan President Otto Perez, Honduras President Juan Orlando Hernandez, and El Salvador President Salvador Sanchez Ceren on July 25 would take place at the White House. Vice President Joe Biden, who has met with the leaders during a trip to Central America last month, would host them for lunch.

"The four leaders and Vice President Biden will discuss how to reinforce our ongoing collaboration to stem the flow of undocumented migrants from Central America to Mexico and the United States," the White House said in a statement.

"The leaders will also discuss how we can work together with other members of the international community to foster development, economic growth, and security in the region and address the factors that are causing Central American citizens to undertake the dangerous journey to the United States."

The meeting comes as the Obama administration steps up its efforts to return child migrants to their home countries. More than 40 Central American children were expelled from the United States on flights to Honduras, Guatemala and El Salvador on Friday.